Prognostic Impact of Diabetes Mellitus on Clinical Outcomes in Lean Patients With Acute Myocardial Infarction

Background/Aim: Little is known about the impact of diabetes mellitus (DM) on clinical outcomes in lean patients with acute myocardial infarction (AMI). We conducted this study to evaluate the impact of DM on clinical outcomes in AMI patients based on body mass index (BMI) level. Patients and Methods: A total of 1,282 consecutive AMI patients who underwent emergent percutaneous coronary intervention within 24 hours from onset were retrospectively studied. The patients were divided into 2 groups based on BMI: Underweight group (BMI <18.5 kg/m², n=61) and non-Underweight group (BMI ≥18.5 kg/m², n=1,221). The primary endpoint was all-cause death, and the secondary endpoint was major adverse cardiovascular and cerebrovascular events. The median follow-up period was 3.8 (1.7-5.0) years. Results: The Underweight patients were older and included more females than the non-Underweight patients, and had a lower prevalence of coronary risk factors including DM. The primary and secondary endpoints were significantly higher in the Underweight patients (both p<0.05 by the Log-rank test). When divided by the presence of DM, the secondary endpoint was significantly higher in the non-Underweight patients with DM than in those without DM (p<0.05). However, there was no significant difference between Underweight patients with DM and those without DM. Multivariate analyses showed that DM was an independent predictor for the primary and secondary endpoints in non-Underweight patients, but not in Underweight patients. Conclusion: DM was associated with worse clinical outcomes in normal-weight or obese AMI patients, but not in underweight AMI patients.